'use strict'

const autoprefixer            = require('autoprefixer')
const path                    = require('path')
const webpack                 = require('webpack')
const HtmlWebpackPlugin       = require('html-webpack-plugin')
const ExtractTextPlugin       = require('extract-text-webpack-plugin')
const ManifestPlugin          = require('webpack-manifest-plugin')
const InterpolateHtmlPlugin   = require('react-dev-utils/InterpolateHtmlPlugin')
const SWPrecacheWebpackPlugin = require('sw-precache-webpack-plugin')
const eslintFormatter         = require('react-dev-utils/eslintFormatter')
const ModuleScopePlugin       = require('react-dev-utils/ModuleScopePlugin')

const paths                   = require('./paths')
const getClientEnvironment    = require('./env')

// Webpack uses `publicPath` to determine where the app is being served from.
// It requires a trailing slash, or the file assets will get an incorrect path.
const publicPath = paths.servedPath

// Some apps do not use client-side routing with pushState.
// For these, "homepage" can be set to "." to enable relative asset paths.
const shouldUseRelativeAssetPaths = publicPath === './'

// `publicUrl` is just like `publicPath`, but we will provide it to our app
// as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.
// Omit trailing slash as %PUBLIC_URL%/xyz looks better than %PUBLIC_URL%xyz.
const publicUrl = publicPath.slice(0, -1)

// Get environment variables to inject into our app.
const env = getClientEnvironment(publicUrl)

// Assert this just to be safe.
// Development builds are slow and not intended for production.
if (env.stringified['process.env'].NODE_ENV !== '"production"') {
	throw new Error('Production builds must have NODE_ENV=production.')
}

// Note: defined here because it will be used more than once.
const cssFilename = 'static/css/[name].[contenthash:8].css'

// ExtractTextPlugin expects the build output to be flat.
// (See https://github.com/webpack-contrib/extract-text-webpack-plugin/issues/27)
// However, our output is structured with css, js and media folders.
// To have this structure working with relative paths, we have to use custom options.
const extractTextPluginOptions = shouldUseRelativeAssetPaths
  ? // Making sure that the publicPath goes back to to build folder.
	{ publicPath: Array(cssFilename.split('/').length).join('../') }
  : {}

// This is the production configuration.
// It compiles slowly and is focused on producing a fast and minimal bundle.
// The development configuration is different and lives in a separate file.
let webpack_prod_config = {
	// Don't attempt to continue if there are any errors.
	bail: true,

	// We generate sourcemaps in production. This is slow but gives good results.
	// You can exclude the *.map files from the build during deployment.
	devtool: 'source-map',

	// In production, we only want to load the polyfills and the app code.
	entry: [require.resolve('./polyfills'), paths.appIndexJs],
	output: {
		// The build folder.
		path: paths.appBuild,

		// Generated JS file names (with nested folders).
		// There will be one main bundle, and one file per asynchronous chunk.
		// We don't currently advertise code splitting but Webpack supports it.
		filename: 'static/js/[name].[chunkhash:8].js',
		chunkFilename: 'static/js/[name].[chunkhash:8].chunk.js',

		// We inferred the "public path" (such as / or /my-project) from homepage.
		publicPath: publicPath,

		// Point sourcemap entries to original disk location
		devtoolModuleFilenameTemplate: info => path.relative(paths.appSrc, info.absoluteResourcePath),
	},

	resolve: {
		// This allows you to set a fallback for where Webpack should look for modules.
		// We placed these paths second because we want `node_modules` to "win"
		// if there are any conflicts. This matches Node resolution mechanism.
		// https://github.com/facebookincubator/create-react-app/issues/253
		modules: ['node_modules', paths.appNodeModules].concat(
	  		// It is guaranteed to exist because we tweak it in `env.js`
	  		process.env.NODE_PATH.split(path.delimiter).filter(Boolean)
		),

		// These are the reasonable defaults supported by the Node ecosystem.
		// We also include .tag as a common component filename extension to support
		// some tools, although we do not recommend using it, see:
		// https://github.com/facebookincubator/create-react-app/issues/290
		extensions: ['.js', '.json', '.tag'],
		alias: {
		},

		plugins: [
			// Prevents users from importing files from outside of src/ (or node_modules/).
			// This often causes confusion because we only process files within src/ with babel.
			// To fix this, we prevent you from importing files out of src/ -- if you'd like to,
			// please link the files into your node_modules/ and let module-resolution kick in.
			// Make sure your source files are compiled, as they will not be processed in any way.
			new ModuleScopePlugin(paths.appSrc),
		],
	},

	module: {
		strictExportPresence: true,
		rules: [
			// Disable require.ensure as it's not a standard language feature.
			// We are waiting for https://github.com/facebookincubator/create-react-app/issues/2176.
			{ parser: { requireEnsure: false } },

			// First, run the linter.
			// It's important to do this before Babel processes the JS.
			{
				test: /\.(js|tag)$/,
				enforce: 'pre',
				use: [
					{
						options: {
							formatter: eslintFormatter,
						},
						loader: require.resolve('eslint-loader'),
					},
				],
				include: paths.appSrc,
			},

			// ** ADDING/UPDATING LOADERS **
			// The "file" loader handles all assets unless explicitly excluded.
			// The `exclude` list *must* be updated with every change to loader extensions.
			// When adding a new loader, you must add its `test`
			// as a new entry in the `exclude` list in the "file" loader.

			// "file" loader makes sure those assets end up in the `build` folder.
			// When you `import` an asset, you get its filename.
			{
				exclude: [
					/\.html$/,
					/\.js$/,
					/\.tag$/,
					/\.css$/,
					/\.less$/,
					/\.json$/,
					/\.svg$/,
					/\.bmp$/,
					/\.gif$/,
					/\.jpe?g$/,
					/\.png$/,
				],
				loader: require.resolve('file-loader'),
				options: {
					name: 'static/media/[name].[hash:8].[ext]',
				},
			},


			// SVG loader
			// https://github.com/webpack-contrib/svg-inline-loader
			// load svg as plain/html
			// example usage:
			//  import myiconhtml from '../icons/myicon.svg'
			//  this.root.innerHTML = require('../../icons/' + this.opts.src)
			{
				test: /\.svg$/,
				loader: 'svg-inline-loader'
			},

			// "url" loader works just like "file" loader but it also embeds
			// assets smaller than specified size as data URLs to avoid requests.
			{
				test: [/\.bmp$/, /\.gif$/, /\.jpe?g$/, /\.png$/],
				loader: require.resolve('url-loader'),
				options: {
					limit: 10000,
					name: 'static/media/[name].[hash:8].[ext]',
				},
			},

			// Riot tag compiler
			{
			   test: /\.tag$/,
			   enforce: 'pre',
			   include: paths.appSrc,
			   exclude: /node_modules/,
			   use: [
				  {
					 loader: require.resolve('riot-tag-loader'),
					 options: {
						type: 'es6',
						debug: false,
						// add here all the other riot-compiler options
						// http://riotjs.com/guide/compiler/
						// template: 'pug' for example
					 }
				  }
			   ]
			},

			// Process JS with Babel.
			{
				test:    /\.(js|tag)$/,
				include: paths.appSrc,
				loader:  require.resolve('babel-loader'),
				options: { presets: 'es2015-riot' }

			},

			// The notation here is somewhat confusing.
			// "postcss" loader applies autoprefixer to our CSS.
			// "css" loader resolves paths in CSS and adds assets as dependencies.
			// "style" loader normally turns CSS into JS modules injecting <style>,
			// but unlike in development configuration, we do something different.
			// `ExtractTextPlugin` first applies the "postcss" and "css" loaders
			// (second argument), then grabs the result CSS and puts it into a
			// separate file in our build process. This way we actually ship
			// a single CSS file in production instead of JS code injecting <style>
			// tags. If you use code splitting, however, any async bundles will still
			// use the "style" loader inside the async code so CSS from them won't be
			// in the main CSS file.
			{
				test: /\.css$/,
				loader: ExtractTextPlugin.extract( Object.assign({
					fallback: require.resolve('style-loader'),
					use: [
						{
							loader: require.resolve('css-loader'),
							options: {
								importLoaders: 1,
								minimize: true,
								sourceMap: true,
							},
						},
						{
							loader: require.resolve('postcss-loader'),
							options: {
								ident: 'postcss', // https://webpack.js.org/guides/migrating/#complex-options
								plugins: () => [
									require('postcss-flexbugs-fixes'),
									autoprefixer({
										browsers: [
											'>1%',
											'last 4 versions',
											'Firefox ESR',
											'not ie < 9', // React doesn't support IE8 anyway
										],
										flexbox: 'no-2009',
									}),
								],
							},
						},
					],
				}, extractTextPluginOptions )
				),

				// Note: this won't work without `new ExtractTextPlugin()` in `plugins`.

			},

			// ** STOP ** Are you adding a new loader?
			// Remember to add the new extension(s) to the "file" loader exclusion list.

		],
	},

	plugins: [
		new webpack.ProvidePlugin({
			riot:  'riot',
		}),

		// Makes some environment variables available in index.html.
		// The public URL is available as %PUBLIC_URL% in index.html, e.g.:
		// <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
		// In production, it will be an empty string unless you specify "homepage"
		// in `package.json`, in which case it will be the pathname of that URL.
		new InterpolateHtmlPlugin(env.raw),

		// Generates an `index.html` file with the <script> injected.
		new HtmlWebpackPlugin({
			inject:   true,
			template: paths.appHtml,
			minify: {
				removeComments:                true,
				collapseWhitespace:            true,
				removeRedundantAttributes:     true,
				useShortDoctype:               true,
				removeEmptyAttributes:         true,
				removeStyleLinkTypeAttributes: true,
				keepClosingSlash:              true,
				minifyJS:                      true,
				minifyCSS:                     true,
				minifyURLs:                    true,
			},
		}),

		// Makes some environment variables available to the JS code, for example:
		// if (process.env.NODE_ENV === 'production') { ... }. See `./env.js`.
		// It is absolutely essential that NODE_ENV was set to production here.
		// Otherwise React will be compiled in the very slow development mode.
		new webpack.DefinePlugin(env.stringified),

		// Minify the code.
		new webpack.optimize.UglifyJsPlugin({
			compress: {
				warnings: false,
				// Disabled because of an issue with Uglify breaking seemingly valid code:
				// https://github.com/facebookincubator/create-react-app/issues/2376
				// Pending further investigation:
				// https://github.com/mishoo/UglifyJS2/issues/2011
				comparisons: false,
			},
			output: {
				comments: false,
			},
			sourceMap: true,
		}),

		// Note: this won't work without ExtractTextPlugin.extract(..) in `loaders`.
		new ExtractTextPlugin({
			filename: cssFilename,
		}),

		// Generate a manifest file which contains a mapping of all asset filenames
		// to their corresponding output file so that tools can pick it up without
		// having to parse `index.html`.
		new ManifestPlugin({
			fileName: 'asset-manifest.json',
		}),

		// Generate a service worker script that will precache, and keep up to date,
		// the HTML & assets that are part of the Webpack build.
		new SWPrecacheWebpackPlugin({
			// By default, a cache-busting query parameter is appended to requests
			// used to populate the caches, to ensure the responses are fresh.
			// If a URL is already hashed by Webpack, then there is no concern
			// about it being stale, and the cache-busting can be skipped.
			dontCacheBustUrlsMatching: /\.\w{8}\./,
			filename: 'service-worker.js',
			logger(message) {
				if (message.indexOf('Total precache size is') === 0) {
					// This message occurs for every build and is a bit too noisy.
					return
				}
				console.log(message)
			},
			minify: true,
			// For unknown URLs, fallback to the index page
			navigateFallback: publicUrl + '/index.html',
			// Ignores URLs starting from /__ (useful for Firebase):
			// https://github.com/facebookincubator/create-react-app/issues/2237#issuecomment-302693219
			navigateFallbackWhitelist: [/^(?!\/__).*/],
			// Don't precache sourcemaps (they're large) and build asset manifest:
			staticFileGlobsIgnorePatterns: [/\.map$/, /asset-manifest\.json$/],
			// Work around Windows path issue in SWPrecacheWebpackPlugin:
			// https://github.com/facebookincubator/create-react-app/issues/2235
			stripPrefix: paths.appBuild.replace(/\\/g, '/') + '/',
		}),

		// Moment.js is an extremely popular library that bundles large locale files
		// by default due to how Webpack interprets its code. This is a practical
		// solution that requires the user to opt into importing specific locales.
		// https://github.com/jmblog/how-to-optimize-momentjs-with-webpack
		// You can remove this if you don't use Moment.js:
		new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/),
	],

	// Some libraries import Node modules but don't use them in the browser.
	// Tell Webpack to provide empty mocks for them so importing them works.
	node: {
		fs:  'empty',
		net: 'empty',
		tls: 'empty',
	},
}



// LESS loader
if (process.env.enable_less){
	webpack_prod_config.module.rules.push({
		test: /\.less$/,
		use: [
			// creates style nodes from JS strings
			{ loader: 'style-loader' },
			// translates CSS into CommonJS
			{ loader: 'css-loader'   },
			// compiles Less to CSS
			{ loader: 'less-loader'  }
		]
	})
}

// SASS loader
if (process.env.enable_sass){
	webpack_prod_config.module.rules.push({
		test: /\.(scss|sass)$/,
		use: [
			// creates style nodes from JS strings
			{ loader: 'style-loader' },
			// translates CSS into CommonJS
			{ loader: 'css-loader'   },
			// compiles Sass to CSS
			{ loader: 'sass-loader'  }
		]
	})
}

// STYLUS loader
if (process.env.enable_stylus){
	webpack_prod_config.module.rules.push({
		test: /\.styl$/,
		use: [
			// creates style nodes from JS strings
			{ loader: 'style-loader' },
			// translates CSS into CommonJS
			{ loader: 'css-loader'   },
			// compiles stylus
			{ loader: 'stylus-loader'  }
		]
	})
}


module.exports = webpack_prod_config
